Assessment of Land Cover Change in Peri-Urban High Andean Environments South of Bogotá, Colombia

Abstract

Bogotá, the rapidly growing center of an emerging economy in the northern part of South America, is located within a biodiversity hotspot in the tropical Andes. The surrounding mountains harbor the ecosystems Páramo and Bosque Altoandino whose high water retention capacity serves as a "natural water tower" for the city's freshwater supply. Since Bogotá is steadily growing, the city spreads into its peri-urban area, thus threatening its proximal ecosystems. In this study, the land use and land cover change (LULCC) of Bogotá's surrounding area is analyzed with random forest algorithms for the period 1989 to 2016. The basin of the Rio Tunjuelo, a subbasin of the Rio Bogotá, was selected for analysis, as it is typical for the entire area in terms of relief, land use and land cover. A multiple logistic regression analysis is applied to identify different determining factors of the changes. LULCC analysis of the Rio Tunjuelo basin shows an ongoing but abating southward spread of Bogotá's outer rim, an increase of agricultural land, and decrease of natural vegetation. After an initial heavily spatial spread of urbanization in the early 1990s, the speed of urban spread declined in the past years. Statistical analysis implies that the defined natural vegetation classes must be considered as one spatial entity. The probability for their change increases with decreasing distance to established agricultural areas, which indicates human impact as a relevant factor for LULCC. Generally, the explained deviance (D 2) is low and hence it is presumed that the LULCC determining factors are not predominantly found among environmental parameters.

Dynamics of Land Use and Land Cover Changes in Harare, Zimbabwe: A Case Study on the Linkage between Drivers and the Axis of Urban Expansion

“…A collection of 6139 random sample points was assembled, and the remaining outliers were removed because they were scattered outside of the rasters. Extracted distance proximity parameter values were log-transformed and, during computation, a 30 m value equivalent to cell length was added to all cells in order to counter undefined 0 logarithm for predictors applied in the regression analysis [46]. The statistical significance of p < 0.05 indicated that the relation between predictor and LULC change occurrences were not random, highlighting a statistical relation between the independent proximity variable and an urban built-up area.…”

Assessment of Land Cover Changes in the Hinterland of Barranquilla (Colombia) Using Landsat Imagery and Logistic Regression

“…When connected with GIS, binomial logistic regression is an appropriate tool for explanatory analysis of the factors of land cover changes [31,57,60]. Accordingly, we used logistic regression models to identify drivers and determining factors leading to vegetation cover changes.…”

“…The True Positive Rate gives the proportion of correctly classified positive sampling points. The True Negative Rate is the proportion of the correctly classified negative sampling points [31,61].…”

“…Over the past years the southern areas of Barranquilla and Soledad received the majority of Colombians displaced by the armed conflict and a considerable influx of migrants from Venezuela [21]. The trends in Barranquilla, such as urban sprawl, segregation, re-densification and urban growth along primary streets, are similar to other cities in the Global South, although each city has its individual characteristics [26,28,31,72,73]. A decisive characteristic of Barranquilla represents its location at the mouth of the Magdalena River, and hence the city development is limited to the north and east.…”

Understanding Land Use Changes in the Central High-Andean Moist Puna

“…GIS provides a flexible environment for a rapidly developing data processing and analysing for change detection in a study area. In high-Andean mountains, most previous land-use change studies using GIS focused on a peri-urban interface [8], [9], or a watershed [10]- [14], or a specific ecosystem [15]- [18], but not much research has been done across multiple provincial boundaries. In Peru, land planning at local level is regulated by provincial municipalities (Organic Law of Municipalities No.…”